1. Field of the Invention
This invention relates generally to an end of the paper roll detection assembly, and in particular to an end of the paper roll detection assembly which automatically signals the approaching end of a toilet paper roll.
2. Prior Art
Conventionally, there have been many types of paper roll end detecting devices which indicate a small amount of remaining paper on a roll. Approaching the end of the paper roll is most often detected visually. However, such visual detection is often not practical in public rest rooms in locations such as gas stations, restaurants and the like.
The end of the paper roll signaling devices have been described by a number of inventors. Bolick, in U.S. Pat. No. 3,820,101, determines the end of a paper roll with the use of a radiation, such as light. The radiation path remains interrupted on the spool until only a predetermined amount of tape remains on the spool. Kishioka, U.S. Pat. No. 3,409,242 determines the diameter of a rolled sheet by pulses which are applied to a step-wave producing element, the output of which is applied to the density. This raises the voltage to a reference voltage level. In turn a signal is produced which can be utilized to recognize that a rolled sheet has run short of or exceeded a predetermined diameter. Hiler, U.S. Pat. No. 3,492,732 describes a supply roll with two follower members which engage the circumference surface of the web and web support respectively. The follower members sense a differential quantity of the web material on the roll and according to predetermined conditions provide an indication thereof. Nedstedt, U.S. Pat. No. 4,620,184 details a sensing device on material rolls, used to give advance warning when the material web forming the roll approaches its end. The sensing device comprises a magnetic field generating element and a sensing device such as a heavy current switch. The heavy current switch which is acted upon at a certain predetermined field strength, indicating that roll replacement is necessary. Finally, Usui, U.S. Pat. No. 4,204,180 describes an adjustable paper roll retaining member and detecting bar. When paper is consumed the paper roll core lowers toward the retaining member until the core is aligned with the detecting bar. The detecting bar enters into the hollow core actuating a switch that generates a signal. This signal indicates that a predetermined amount of paper remains on the roll.
The invention provides adequate detection of the end of the roll, and signals personnel in an area remote to the rest room that the tissue is running low, thus enabling the personnel to replace the tissue before customers are inconvenienced.